David Cameron inched closer to promising a referendum on the EU today after he admitted a "fresh settlement" was coming.
Speaking to the Today programme the Tory leader said a new form of consent had to be secure once the UK's relationship with a reformed EU had crystallised.
"I've always said that when we achieve that fresh settlement, it needs consent either at a referendum or a general election," he said.
"But the referendum is obviously the cleanest, neatest, simplest and most sensible way of doing that."
The comments suggest Tory HQ is increasingly jittery about the effect Ukip could have on the party at the general election.
Polls released yesterday suggested the prime minister would need a "miracle" to secure a majority in 2015. If Ukip chips away at the Tory vote from the right, it could further destabilise the campaign.
Cameron's comments also reflect a growing consensus among the political class that Britain's relationship with a new EU would require some new form of consent for it to have any democratic legitimacy.
Ed Miliband also toyed with the idea of offering a referendum, but stopped short of making any concrete pledges. If anything, Labour is more divided on the EU than the Tories, although the issue has historically had less of an impact on the party.